(JHAi'. XXVIII. BY CUTTINGS AND LAYERS. 487 



It was found that the cbincliona} are remarkably impatient 

 of any dam]) at their roots, all the si)ecies tlirive better in 

 rough and oi^en than in fine soil, and there is reason to believe 

 that they will bear a much drier climate than we originally 

 supposed. 



During the autumn of 1861 the work of i)ropagation, by 

 means of cuttings and layers, progressed rapidly ; and, whereas 

 in June 1861 we only had 2114 chinchona-plants of valuable 

 species at Ootacamund, in January the number was increased 

 to 9732 plants. The layers of C. succirubra root sufficiently 

 to be removed in five weeks, and cuttings in two months ; 

 layers of the '" grey-bark " taking a little longer time to root, 

 or about six weeks. Mr. Mclvor has also made the important 

 discovery that cliiuchonfe strike freely from eyes, and make 

 beautiful plants exactly like strong seedlings. These eyes will 

 give about eight fine strong plants for one that is obtained 

 from cuttings, which is a great advantage while there is not 

 much wood in the young plants. In October Mr. Mclvor re- 

 duced the temperature of one of the propagating houses to 55° 

 at night, and 65° during the day ; and, under this treatment, 

 which is also probably advantageous to the bark, the plants 

 appeared to grow faster, and the leaves became a veiy beau- 

 tiful bright green. The thickness of the bark, in the plants 

 of C. succirubra, is very remarkable, ha^•ing been in some in- 

 stances nearly one-seventh of an inch last January, and in 

 the smaller stems the average thickness of the bark consider- 

 ably exceeds that of the Avood. Mr. Mclvor attributes the 

 unusual thickness of the bark to the presence of a large 

 number of healthy leaves, exposed to bright light. These 

 leaves throw back into the bark a large quantity of highly 

 elaborated matter. The exijerience of a year's cultivation 

 convinced BIr. Mclvor that, although the most suitable eleva- 

 tion and climate differs with the various species, yet that they 

 all require a rich, rough, and very oi)en soil. In September 

 the erection of a new propagating house for chinchona-plants, 



